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Induction hardening is a heat treatment technique that can be used to harden specific portions of gears to improve their mechanical properties - Leaving Cert Engineering - Question c - 2022
Question c
Induction hardening is a heat treatment technique that can be used to harden specific portions of gears to improve their mechanical properties. (i) Describe, with t... show full transcript
Worked Solution & Example Answer:Induction hardening is a heat treatment technique that can be used to harden specific portions of gears to improve their mechanical properties - Leaving Cert Engineering - Question c - 2022
Step 1
Describe, with the aid of a diagram, the heating and cooling process used in induction hardening.
Answer
Induction hardening is a process that utilizes electromagnetic induction to heat the surface of a metal part rapidly. This process consists of two primary steps: heating and cooling.
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Heating: A copper coil carrying a significant level of alternating current creates an electromagnetic field. When the workpiece, typically made of steel, is placed within this field, it heats up due to induced currents. The metal reaches the austenitizing temperature, around 800-900°C, which is the temperature range necessary for the phase transformation of steel.
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Cooling: After the workpiece is sufficiently heated, it is quenched, often using jets of water, to rapidly cool the surface. This rapid cooling transforms the heated surface layer into martensite—a harder structure—while maintaining a tougher, softer core.
The entire process is critical for enhancing the mechanical properties of gears, ensuring they are tough yet wear-resistant. Examples of this process apply to applications like slide-ways on center lathes or various gear types.
Step 2
Outline two safety hazards associated with the induction hardening process.
Answer
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High Temperatures: The heating process involves very high temperatures that can cause burns or injuries. Therefore, wearing proper Personal Protective Equipment (PPE) is essential to shield against heat exposure.
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Electrical Hazards: The induction coil runs on electrical alternating current, which can lead to electrical shocks if there are faults in the circuit. Proper electrical safety measures and regular maintenance are crucial to prevent electrical hazards.